Алтайская этимология :

Комментарии:A Western isogloss. The stem may be derived from Common Altaic *úmu 'to bear, give birth' q. v., see АПиПЯЯ 58, 281, Дыбо 10, Лексика 149. The Turkic form, however, must have also been influenced by PA *nā̀mo 'testicle' (and/or *ǯi̯ŏmu `round'), which explains initial *j-.

Комментарии:Tamil muṭṭai, Mal. muṭṭa due to contamination with muttai 'lump' (at least, this is a far more probable explanation than setting up an extraordinary umlaut case before a voiceless consonant). Tamil muṇṭai unclear.